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DDDD DDDD is offline
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Join Date: Jan 2007
Posts: 1,077
Quote:
Originally Posted by Miguel Antonett View Post
That's a clean looking machine!

The tach gauge is not that acurate, if it was at .8 before the changes it should be OK. Considering you did not change the WG spring.
I've got to respectfully disagree with that.

When you put new, short headers on a 930 it can overboost quite easily. Some cars overboost or get boost creep which means the wastegate no longer bleeds boost as fast as it builds. This is because the exhaust is sending air to the turbo much quicker than before, yet the pipe going to the wastegate might not be flowing as well, if it is turning back with a couple 90 degree bends.

It all depends on how accurate a boost gauge you have. The factory gauge wasn't great but the aftermarket gauges that replace the clock are usually okay, and if it used to say .8 bar and now says 1 bar, guess what?

I wouldn't worry if it is bleeding off pressure at 1 bar or ever so slightly over, as long as you tune your AFR correctly to compensate for a little more boost.

But if you are creeping to 1.1 bar or more than you may want to reduce the spring in your wastegate to less than .8 bar and run a manual boost controller to make up the difference, the Hallman pro RX with a ceramic ball is the boost controller I just bought. Greddy makes a couple really simple and good electronic boost controllers if you want more control, but the manual ball and springs types are supposed to be good enough.
Old 08-11-2007, 10:11 PM
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